MVC audio controls playing song from bytes

One way would be to add a new action in your controller that returns the data:

public ActionResult Audio(int someId)
{
    byte[] songBytes; 
    // Add code to get data
    return new FileStreamResult(songBytes, "audio/mp3");
}

Then put the URL to that into the src attribute:

foreach (var item in Model)
{
    <audio controls>
        <source src="/Controller/Audio/@item.someId" type="audio/mp3"/>
    </audio>  
}